Dual torque indicator

ABSTRACT

A meter for indicating two related functions together with the summation of the values of the two functions by means of a pair of coaxially, separately driven pointers cooperating with a scale on a fare plate behind the needles and a function summation unit driving a pointer behind the fare plate and extending at least in part in front of the fare plate in cooperation with a second scale thereon.

United States Patent Brindley et al.

451 Apr. 4, 1972 541 DUAL TORQUE INDICATOR [72] Inventors: Hanby S.Brindley, Arlington; John A. Buyers, Jr., Fort Worth; Turpin Gerard,Euless; John S. McClung, Jh, Hurst, all of [21] Appl. No.: 882,260

3,091,214 5/1963 Hoffman ..1l6/129 3,135,119 6/1964 Hauptman. ..73/5103,483,758 12/1969 Munden ..73/510 X OTHER PUBLICATIONS Aircraft Pressureand Load Systems" Fairchild Control Bulletin, Oct. 16, 1964 PrimaryExaminer-Charles A. Ruehl Attorney-Richards, Harris & Hubbard and GeorgeGalerstein [57] ABSTRACT [52] U.S. Cl ..73/l38, 73/432 A, 116/129 R I 5100 A meter for indicating two related functions together with the [58]Field of Search ..73/l36 R, 137, 138, 432 R; Summation 0f the values ofthe two functions y means of a 1 16/129. 235/1 19 120 pair of coaxially,separately driven pointers cooperating with a scale on a fare platebehind the needles and a function summa- I 56] References Cited tionunit driving a pointer behind the fare plate and extending at least inpart in front of the fare plate in cooperation with a UNITED STATESPATENTS Second al th reon- 2,538,843 l/195l McGuire ..73/432 A UX 8Claims, 4 Drawing Figures 380 W. 3* no;

7o 23 46 l Q 50 DUAL TORQUE INDICATOR This invention relates toinstruments for use in an aircraft and more particularly to aninstrument to display two related functions and the summation thereof.

BACKGROUND OF THE INVENTION l-Ieretofore aircraft torque indicators haveseparately indicated the torque from the aircraft engine or engines.Recent advances in the design of helicopters have brought about theextensive use of dual engine aircraft. With such aircraft the pilotneeds to know the combined torque output of the two engines as well asthe torque output of each individual engine. For ease of use by pilots,a torque indicator should provide a display which is uncluttered and iseasy to read. Other related functions are also to be displayed such asfuel flow, fuel quantity, etc.

The present invention provides an instrument which continuously displaysthe magnitude of two related functions together with the value of thesum of the functions in a presentation which is uncluttered and easilyread.

SUMMARY In accordance with the present invention an indicator isprovided to display a pair of variable functions and the sum thereof.The indicator includes a meter scale plate having a pair of graduatedarcuate scales symmetrical about an axis. A pair of pointers coaxiallyare mounted for independent rotation about the axis in front of theplate. Driving means drive the pointers, one in accordance with each ofthe two func tions. The indicator also includes means for summing thetwo functions. A pointer supported for rotation behind the plate extendsat least in part in front of the scale plate and moves in accordancewith the sum of the two functions in cooperation with a second arcuatescale on the scale plate to indicate the summation value.

THE DRAWINGS For a more complete understanding of the invention and forfurther advantages thereof, reference may now be had to the followingdescription taken with the accompanying drawings in which:

FIG. 1 is an illustration of the face of a torque indicator;

FIG. 2 is a bottom view of the indicator partially sectioned along line2-2 of FIG. 4;

FIG. 3 is a partially sectioned schematic elevation of the interior ofthe indicator;

FIG. 4 is a diagrammatic representation which shows the relativelocations of the principal elements of the indicator assembly.

DESCRIPTION OF A PREFERRED EMBODIMENT FIGURE 1 FIG. 1 shows the face ofa dual torque indicator as employed to indicate the torque of dualengines on a helicopter. The indicator is a panel mounted instrumentwhich includes a meter scale plate 11, a first pointer 12, a secondpointer 14, and a rotating cursor 15. The meter scale plate 11 containsa graduated arcuate inner scale 16, and a graduated arcuate outer scale18. An arcuate slot 19in the meter scale plate 11 separates inner scale16 from outer scale 18. Pointer 12 rotates about axis 20 near the centerof the meter scale plate 11. Pointer l2 cooperates with inner scale 16to to indicate functional values from one engine. The second pointer 14is shaped distinctively from the first pointer 12 so that each pointercan be easily identified. The second pointer 14 also rotates about axis20 and cooperates with the inner scale 16 to indicate like functionalvalues from a second engine. The rotating cursor moves within slot '19and by means of the cursor pointer 15a cooperates with the outer scale18 to indicate the sum of the values shown by the first pointer 12 andthe second pointer l4.

nouns 2 FIG. 2 is a partially sectioned bottom view of the front portionof the indicator. A first torquer motor 21 drives a shaft 22 and a firstdrive gear 23. Gear 23 engages a first transmission gear 24 which isintegrally fastened to a shaft 25 on which pointer 12 is mounted so asto rotate with shaft 25.

A second motor 26 has a shaft 28 on which a second drive gear 29 ismounted. Gear 29 drives a second transmission gear 30 which is rigidlyattached to a concentric tubular axial shaft 31. Pointer 14 is mountedon shaft 31. Shaft 31 is separated from shaft 25 by means of a slip ring36.

The end of the instrument case 32 which houses the dual torque indicatoris shown unsectioned in FIG. 2. The forward end 34 of the instrumentcase 32 has a rib of greater diameter than the remainder of the case toprovide a stop 35 for mounting the case in an opening in an aircraftinstrument panel.

The meter scale plate 11 as shown in FIG. 2 is located immediatelybehind the pointers 12 and 14. A first mounting plate 38 is positionedwithin the housing immediately in front of motors 21 and 26. Motors 21and 26 are mounted on plate 38. Instrument ball bearings 39 are alsosecured in plate 38 to provide bearings for shaft 25. A second mountingplate 40 is located forward of gear 29 and is secured to plate 38 byspacers 38a (FIG. 3). Plate 40 supports guideposts 41 and 42 and forms acylindrical shaft housing 44.

Bearings 45 and 46 are fastened to the interior cylindrical opening inthe housing 44 and provide bearing surfaces for the concentric shaft 31.Housing 44 has a reduced outside diameter toward its forward end formingan axial mounting 44a upon which the cursor carrier wheel 47 is mounted.Ball bearing topping hobs 80 and 81 are mounted on posts 41 and 42 andfit into a groove on the outer rim of the cursor carrier wheel 47 topermit rotational movement of the wheel while preventing wobble or otherundesirable motion by the wheel.

FIGURE 3 FIG. 3 is a partially sectioned elevation view of theindicator. The indicator is encased in a compartment formed by case 32,which is closed by front window 48. An electrical receptacle 50 ismounted on and extends from the back side of rear plate 49 to permitconnection to outside electrical circuits (not shown).

Suitable electronics convert input signals received from engines into DCelectric currents to control movement of the torquer motors 21 and 26(see FIG. 2) to drive gears 23 and 29. Gear 23 enmeshes gear 24 (seeFIG. 2) which in turn enmeshes and drives the first input differentialgear 62 of the differential 64.

Gear 29 enmeshes gear 30 which in turn drives the second inputdifferential gear 65. The differential 64 produces a rotation of shaft66 which is equal to the average of the rotation supplied to thedifferential 64 by gears 62 and 65. The gear 68 is mounted on shaft 66so that motion of the shaft 66 is directly transmitted to gear 68 whichis enmeshed with gear 69. Gear 69 is an integral part of the cursorcarrier wheel 47. Cursor 15 is attached to wheel 47 by means of screw70. Cursor 15 consists of a pointer 15a which cooperates with the outerscale 18 (see FIG. 1) on plate 11 and is located forward of plate 11. Italso includes a connecting member 15b which is joined to pointer 15a andis secured to wheel 47 by means of screw 70 and passes through slot 19in plate 11 (see FIG. 1). Bearings 71 and 72 support the differentialoutput shaft 66.

A lamp assembly 74 is attached to plate 40 and cooperates with collar 76to secure a lighting prism against ring 78 which in turn is securedagainst window 48. Lamp 74 and prism 75 provide illumination of themeter scale plate 11 and the pointers which cooperate therewith.

FIGURE 4 FIG. 4 is a diagrammatic representation which shows therelative locations of the principal elements of the indicator.

The instrument case 32 surrounds the entire indicator. The separatorring 78 separates the window 48 (FIG. 3) from the lighting prism 75.Ring 78 lies immediately within the inner edge of case 32. Centered on acircle of slightly smaller diameter than than of the inner edge of ring78 are three ball bearings 79, 80 and 81 which engage the outer edge ofwheel 47. The slot 19 in plate 11 has an outside diameter which isslightly smaller than that of wheel 47. Cursor 15 is driven by wheel 47along the slot 19 and has a pointer 15a which cooperates with the outerscale 18.

A first set of gears which includes gears 69, 30 and 24, and a secondset which includes gears 68, 65 and 62, have equal diameters. In FIG. 4,gears 68, 65, 62 are indicated by a single circle to show the diameterand the location relative to the axis 20 of three gears. The forwardmostgear is gear 68. Positioned rearward of gear 68 are gear 65 and gear 62.

As shown in FIG. 4, motor 21 is connected through shaft 22, FIG. 2, togear 23 which is enmeshed with gear 24 which in turn is connectedthrough shaft 25 (FIG. 2) to pointer 12. Gear 24 is also enmeshed withgear 62 for rotation of differential 64, FIG. 3.

In a similar manner motor 26 is connected through shaft 28, FIG. 2, togear 29 which is enmeshed with gear which in turn is connected throughshaft 31, FIG. 2, to pointer 14. Gear 30 is also enmeshed with gear 65for rotation of differential 64, FIG. 3, which is connected to shaft 66,FIG. 3, which is rigidly connected to gear 68. Gear 68 is enmeshed withgear 69 which is an integral part of wheel 47 to which the rotatingcursor 15 is attached through slot 19 in plate 11 to enable pointer 15ato cooperate with outer scale 18 of the meter scale plate 11.

In operation, as shown in FIGS. 2 and 3, rotational motion of motor 21is transmitted directly to gear 23 by way of shaft 22. Gear 23 isenmeshed with gear 24 so that the motion is transmitted to gear 24 whichin turn rotates pointer 12 through shaft 25.

Rotational motion imparted to gear 24 is also conveyed to the gear 62.

In a similar manner, rotational motion provided by the torque motor 26is transmitted by way of shaft 28 to drive gear 29 so that the motion isconveyed to gear 30 which in turn rotates pointer 14 through shaft 31.

Rotational motion of gear 30 is also transmitted to differential gear65. Rotational movements of gears 62 and 65 are averaged by thedifferential 64 which imparts the average motion to shaft 66 whichextends the motion to pinion gear 68. Gear 68 drives gear 69 therebymoving the cursor carrier wheel 47. The cursor 15 is affixed to wheel 47so that its angular motion always corresponds to that of thedifferential 64 and therefore represents an average of the movementsindicated by the first pointer 12 and the second pointer 14. Thus,pointer 15a will always be positioned at a point which is half betweenthe angular positions of pointer 12 and pointer 14.

As shown in FIG. 1, the outer scale 18 of the meter scale plate 11 hasgraduations which are twice those of the values for similar angularposition of the inner scale 16. With this relationship between the innerscale 16 and the outer scale 18, the pointer 15a cooperates with theouter scale 18 to indicate the valueof the sum of values designated onscale 16 by pointers l2 and 14 since the sum of the values indicated bythe first and second pointers 12 and 14 is equal to twice the average ofthose values as represented by the angular position of the rotatingcursor 15.

Thus, it may be seen that the preferred embodiment satisfies theobjectives of this invention since it provides a continuous indicationof the torque output or other function of each of two engines and thesummation of the values from the two engines. The values from each oftwo engines are displayed by the indicator with a two pointerpresentation which is easy to read and understand. The summation of theengine values is displayed by a cursor pointer which appears to form anextension of the two pointers when both engines are producing the samevalue function thus essentially providing a single needle appearance.When both engines are not producing equivalent value functions, themethod of driving the cursor through a slot from behind the dial allowsit to be read against the dial as a single pointer or portion of aneedle without the associated problems and cluttered appearance of atypical three needle or pointer presentation.

As shown above, in the preferred embodiment dual torque or other enginefunctions are displayed. The display comprises a meter scale platehaving a pair of graduated scales symmetrical about an axis, a pair ofpointers coaxially mounted for rotation about the axis with means fordriving one of the pointers in accordance with a function of the firstof two engines and means for driving the second pointer in accordancewith a like function of the second engine. The pointers cooperate withone of the graduated scales indicating the values of the functions ofthe engines. The indicator also comprises means for summing thefunctionsprovided by the two engines and a pointer supported forrotation behind the meter scale plate and extending through a circularslot in the scale plate for cooperation with the second or outer scaleto indicate the summation of the function values from the engines. Itwill be appreciated that torque, fuel supply, fuel flow and otherrelated functions may similarly be displayed.

The invention has been described in connection with the foregoingembodiment thereof. It is to be understood that the display may bemechanized in several ways, both electrically and mechanically and thatfurther modifications may now suggest themselves to those skilled in theart. It is intended to cover such modifications as fall within the scopeof the appended claims.

What is claimed is:

1. A meter which comprises:

a. a scale plate having a pair of arcuate scales radially spaced fromeach other and spanned from an axis and having an arcuate slottherethrough between said scales,

b. first and second pointers mounted coaxially for independent rotationin front of said plate,

c. athird pointer mounted for rotation on said axis behind said plateand having a pointer tip extending through said slot cooperating withthe second of said scales, and

d. drive means for causing one of said pointers to move in predeterminedrelation to movement of the other two pointers.

2. The combination set forth in claim 1 wherein said drive meanscomprises separate drive means which cause independent rotation of saidtwo pointers and a differential coupled to said separate drive means todrive said third pointer in dependence upon the sum of the motion ofsaid two pointers.

3. The combination set forth in claim 1 wherein a. one of said first andsecond pointers and a central shaft I form a first rotating assembly;

b. a second of said first and second pointers and a hollow shaftemcompassing said central shaft form a second rotating assembly;

(c) a rotatable member and said third of said pointers supported on saidhollow shaft form a third rotating assembly; and

d. wherein said drive means comprises a differential driven by two ofsaid rotating assemblies which drives-the third of said rotatingassemblies.

4. The combination set forth in claim 3 wherein said rotatable member isa disk and means are provided to engage the rim of said disk tostabilize said third of said pointers.

5. The combination set forth in claim 4 wherein said means to engage therim of said disk include roller means.

6. The combination set forth in claim 4 wherein the rim of said disk isgrooved and roller means in said groove engage said disk to stabilizesaid disk.

'7. A dual torque indicator which comprises:

a. a meter scale plate having a pair of graduated scales thereonsymmetrical about an axis,

b. a pair of pointers coaxially mounted for rotation about said axis,

. means for driving one of said pointers in accordance with a functionof the first of two engines and means for driving the other pointer inaccordance with a like function of the second engine, said pointerscooperating with one of said scales, I

means for summing said functions, and

an indicator supported for rotation behind said plate including a thirdpointer extending through a circular slot in

1. A meter which comprises: a. a scale plate having a pair of arcuatescales radially spaced from each other and spanned from an axis andhaving an arcuate slot therethrough between said scales, b. first andsecond pointers mounted coaxially for independent rotation in front ofsaid plate, c. a third pointer mounted for rotation on said axis behindsaid plate and having a pointer tip extending through said slotcooperating with the second of said scales, and d. drive means forcausing one of said pointers to move in predetermined relation tomovement of the other two pointers.
 2. The combination set forth inclaim 1 wherein said drive means comprises separate drive means whichcause independent rotation of said two pointers and a differentialcoupled to said separate drive means to drive said third pointer independence upon the sum of the motion of said two pointers.
 3. Thecombination set forth in claim 1 wherein a. one of said first and secondpointers and a central shaft form a first rotating assembly; b. a secondof said first and second pointers and a hollow shaft emcompassing saidcentral shaft form a second rotating assembly; (c) a rotatable memberand said third of said pointers supported on said hollow shaft form athird rotating assembly; and d. wherein said drIve means comprises adifferential driven by two of said rotating assemblies which drives thethird of said rotating assemblies.
 4. The combination set forth in claim3 wherein said rotatable member is a disk and means are provided toengage the rim of said disk to stabilize said third of said pointers. 5.The combination set forth in claim 4 wherein said means to engage therim of said disk include roller means.
 6. The combination set forth inclaim 4 wherein the rim of said disk is grooved and roller means in saidgroove engage said disk to stabilize said disk.
 7. A dual torqueindicator which comprises: a. a meter scale plate having a pair ofgraduated scales thereon symmetrical about an axis, b. a pair ofpointers coaxially mounted for rotation about said axis, c. means fordriving one of said pointers in accordance with a function of the firstof two engines and means for driving the other pointer in accordancewith a like function of the second engine, said pointers cooperatingwith one of said scales, d. means for summing said functions, and e. anindicator supported for rotation behind said plate including a thirdpointer extending through a circular slot in said plate for cooperationwith the second of said scales to indicate the said summation function.8. The combination set forth in claim 7 wherein said pair of pointersterminate at a radius from said axis substantially the same as the innerradial margin termination of said third pointer whereby appearance of asingle pointer is effected when said pointers are radially aligned.